Process of manufacturing porcelain articles.



J. A. & B. A. JEFFERY. PROCESS OF MANUFACTURING PORCELAIN ARTICLES. APPLICATION FILEDAUG. I8, 1909 RENEWED JULY 12, I915. 1,171,205. 1 Patented Feb,'8, 1916.

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APPLICAITION FILED AUG. 18. 1909. RENEWED JULY 12, I9I5- 1,171,205 Patented Feb. 18, 1916. I

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JOSEPH AnrHuE EEEERY AND BENJAMIN ALE'EED JEEEEEY, or NEWARK. NEW

JERSEY.

Specification of Letters Patent.

PROCESS OF MANU'EACTI J'RING PORCELAIN ARTICLES.

Patented Feb. ,8, 1916.

Application filed August 18, 1909, Serial No. 513,512. Renewed July 12, 1915. Serial No. 39,519.

To all whom it may concern: Be it, known that we, JOSEPH A. JEEEERY, and BENJAMIN A. 'JEFFERY, of Newark, in the county of Essex, State of New Jersey, have invented certain .new and use Improve ments in Processes of Manufacturing Porcelain Articles, of which the following-is a specification. Q

This invention relates to certain new and useful improvements in the art of manufacturing porcelain articles.

Heretofore in the manufacture of porcelain articles such as spark'plugs, insulators andthe' like it has been thecustom to take the soft clay and mold, throw it, or other wise shape it approximately to the desired contour, and then after allowing it to stand. until it reaches what is known as green or half-hard condition it is placed upon a spindle, or otherwise attached to a suitable revolving element and shaped to the exact contour desired'by means of steel tools held in the hands or otherwise positioned over the surface of. the clay. After the blank has been reduced to the proper size it is allowed to dry and' then-dippedintoa:suitable glaze.

or placed directly into the kiln and fired. This practice results in a great percentage of loss by reason of the-fact that the material has to be allowed to become white hard or bone dry, before being placed in the kiln for firing. Furthermore a considerable variation in the dimensions in the finished or fired ware results from the fact'that there is no accurate means of determining the exact time when a piece of clay or what we term a blank, has reached the half-hard or green condition, this condition depending as -it does on the amount of water or moisture" the blank may contain. Consequently few V if any of the blanks contain the same percentage of water or moisture when'turned placed aside to dry before firing a consider able variation of the dimensions will result of turning the piece is so shaped that the. cross section of some parts is much heavier and more passive than others. In some ingiven the desired contour, and when stances I cracks are formed "in the drying process, andin others a settling and warpmg occurs due in the first case to the light sections drying more rapidly than the heavier and consequently cracking; and in the ing the lightersections unevenly.

The object of the present invention is to overcome these objections by first allowing the blank of the clay comprising the porcelain to become white hard or bone dry. The dry blank is thenshaped to conform to the desired contour and then baked or dried in the usual manner. By following out this because it is impossible to judge the exact percentage of moisture in the clay while be-' ing turned, is replaced by a known and uniform shrinkage which is that between the second case the weight of the piece compressprocess the uncertain" shrinking, uncertain white dry and the dried or finished state.

Therefore the percentage ofloss-by reason of distortion or uneven shrinkage of different portions of the completed article is reduced to a minimum.

The inventlon will'be hereinafter fully set forth and particularly pointed out in the claims. In the accompanying drawings Figure 1 is a front view illustrating our improved apparatus; Fig. 2 is a plan view thereof. Fig. 3 is an endview. Fig. 4: is

an end view illustrating the slight modifica- 7 tion. Fig. 5 is a sectional view illustrating thesecond modification. 'Fig. .6 is, a view illustrating the dry '-blank.;before shaping.

Referring tothe drawings, 10 designates a base or casting of anysuitable or'preferred form provided .withbearings 11 supporting a shaft 12. Said shaftfis rotated by -means of a pulley 13 receiving power from-any suitable source. an abrasive wheel 14 the periphery of which Secured to the shaft 12 is is provided with grooves and ribs to form a pattern con-forming to the shape that isdesiredto give the w'erk. We have found that excellent results are secured bylusing;

a wheel for this purpose constructed of carborundum although we dofnot desire" to limit ourselves in thisparticular as-it is quite obvious that a wheel or drum may be made of any suitable material and prov ded with a,surfaoe of abrasivelmaterial.

Mounted on rods 15 working in the base 10 is a carriage 16 the weight of which 1s normally supported by springs 17 encircling said rods. Said carriage is provlded with suitable bearings for a shaft 18 rotated by means of a pulley 19 receiving power from any suitable source. The shaft 18 projects over'the wheel 14 to form a mandrel for the porcelain blank 19. In the drawlngs the work 19 is illustrated as a porcelain spark plug and the abrasive wheel 14 is of a pattern conforming to the same. Connected to the carriage 16 is a lever 20 pivoted at.

manner by. hand, and finally shaped into cylindrical blanks, suchas illustrated in Fig. 6, and the green blank is then laid aside until it dries to rather a hard condition which we term white or bone dry.-

In this state the clay has become quite hard, and will retain its shape whilebeing handled. A longitudinal bore is formed in the blank in any suitable manner while in the green state or may be ground or otherwise suitably formed in the dry clay. After the blank has become sufl'iciently hard, it is placed upon the mandrel 18 and the lever operated to depress the carriage 16, thereby bringing the blank. in contact with the abrasives wheel 14'which' ,will act upon, cut

orgrind the surface of the blank and shape the latter to conform to the pattern of the former. In carrying out our invention it is our intention to substitute abrasive wheels of different patterns to conform to the work desired, the wheel 14 being shown as removably secured in position. 1 In Fig. 4 we have shown a slight modi fication which consists in employinga plurality of mandrels 30. to receive the work, said mandrels being each rotatably mounted in a revolving head 31 and coiiperating with an abrasive wheel14 as heretofore described.

In practice the mandrels are successively brought around in position to .bring the blank into engagement with the abrasive wheel 14, the operation being otherwise the same as in connection with Fig. 1. By this arrangement the capacity of the apparatusv is greatly increased. In Fig. 5 we a have shown the modification in which the spindle is supported in a vertical position.

In this form the blank 40 rests upon the revoluble face plate carried by a spindle 42 and provided with a mandrel 43. An abrasive wheel 44 may be provided for shaping the bore of the blank, a second abrasive firing.

2. An improvement in the art of manuwheel 45 may provided for engagin' the peri her of the blank. The advantagi of this form is that large pieces of clay, which may weigh up to two hundred pounds or more, can be handled much more easily and with less chance of breakage than would be the case if the spindle were horizontal. When placed on a horizontal'spindle or arbor the work depends, for traction on' fitting tightly-in the arbor. This not only strains the clay causingcracks to develop but may actually break it open. The horizontal arrangement therefore is best adapted forlight'work. On the vertical spindle the work rests on the revolving face platewhich gets its traction by reason of its weight. The pattern wheel 46 may be formed so as to give a finished shape to the work by feeding. it transversely into engagementtherewith as heretofore described, or it may be operated as indicated in Fig; 5 by traversing longitudinally of the blank combined with a'transverse feeding of the wheel, with a art of the profile formed on the latter I desired the holes and grooves maybe roughly formed in soft clay and afterward ground' to finished form when the clay becomes dry. It is understood that ordinarily an abrasive wheel carrying the counterform of the piece desired is to be used on this, vertical form of ma chine. We desire to haveit further understood that while we have illustrated in the drawings certain mechanisms adapted to carry outour improved process of manufacturin porcelain blanks, said drawings are intended for illustrative purposes only and we do not limitmurselves thereto. It is quite obvious that the said process may be carried out in conjunction with various other forms of mechanism without departing from the spirit of our invention.

We claim as our invention 1. An improvement in the art of manufacturing porcelain articles comprising producing blanks of green clay, allowing said blanks to become. dry and hard, imparting the desired shape to'said blanks while in the dry and hard condition by grinding ofl portions of the surface thereof and then facturin porcelain articles comprising producing b anks of plastic clay, allowing said blanks to stand until they are bone dry and brittle, grinding oil the surfaces of the blanks throughout the length thereof to impart the desired shape to said blanks while in the dry and brittle condition and then firing.

3. An improvementin the art of manufacturing porcelain articles comprising probe provided for shaping the top of the blank anda pattern'wheel 46 is 1,171,205 r B I ducing apnrofimately cylindrical. blanks of plastic green clay, allowing the same to stand until bone dry, grinding the surfaces of the blanks to impart an irregular contour of circular cross section to said blanks while in the bone dry condition and then firing. v r b In testimony whereof, we have signed this specification in the presence of two subscribing witnesses.

JOSEPH ARTHUR. murmur. BENJAMIN ALFRED JEFFERY.

Witnesses:

MAGGIE W. SUTPHEN, Josnrn S. SUTPHEN. 

